Question

The first resonance length in a closed organ pipe is $50cm$. Then the second resonance length will be

• A. $50cm$
• B. $100cm$
• C. $150cm$
• D. $200cm$

Answer 1

Answer: (C)

$150cm$

The resonance length in a closed organ pipe is

$l=(2n+1)\frac{\lambda }{4}$

Hence, the first resonance length in a closed organ pipe is

$l_1=\left(2\right(0)+1)\frac{\lambda }{4}$

$l_1=\frac{\lambda }{4}=50cm$ .........................(given)

Now, the second resonance length in a closed organ pipe is

$l_1=\left(2\right(1)+1)\frac{\lambda }{4}$

$l_1=\frac{3\lambda }{4}=\left(3\right)\left(50\right)=150cm$